This invention relates to heat exchange apparatus. More particularly, the invention relates to heat exchange apparatus suitable for removing or abstracting heat from gases which have very high temperatures and pressures and/or contain suspended matter which is subject to deposition in heat-exchanger tubes through which the gases flow. In its preferred form, the apparatus of the invention is particularly suited for generating steam under pressure from the sensible heat in the reaction gas from a plant for the preparation of hydrogen and carbon monoxide by the partial combustion of a hydrocarbon with oxygen, at superatmospheric pressure, optionally with the supply of steam.
Gases produced in many processes, such as partial combustion processes, generally are discharged from their source at temperatures of from 1000.degree. C. to 1500.degree. C. and are, therefore, a potential source of energy. Because of the fact that many such gases contain suspended matter, such as free carbon, heat exchange units of special design are utilized to recover the thermal energy available at the high temperatures. In general, the great temperature differences and high pressures prevailing in such heat exchangers require the apparatus to be of special quality and strength. Heat exchangers comprising helically wound gas cooling pipes are particularly suitable in fulfilling the mechanical requirements. Suitable heat exchangers operating as waste heat boilers for the purpose mentioned above have been described e.g. in British Pat. Spec. Nos. 851,542, 1,332,809 and 1,340,254.
Accordingly, it is an object of the invention to provide a heat exchange apparatus suitable for cooling such high-temperature gases wherein the cooling tubes or pipes through which the hot gases flow are intensively cooled at the entrance point, whereby mechanical difficulties are mitigated, and which apparatus is particularly suitable for operation at high capacities and pressures.